Question: I recently dug a border garden which contained a lot of crabgrass and other weeds. I would like to begin planting some perennials/small trees and ground cover. What kind of weed killer can I use to prevent the weeds from coming back, and should it be applied prior to or after planting the new flowers?

Answer: There are some pre-emergent herbicides on the market that can be incorporated into the top 3" of soil after planting your perennials. Or, you can line the bed with one of the poly-spun fabric weed barriers, cutting holes in the fabric to plant your perennials, shrubs and trees. You can cover the weed barrier with decorative rock or bark, or plant groundcover to disguise its presence.